论文标题
缩放缩放改进了近壁湍流运动的内盘分解
A scaling improved inner-outer decomposition of near-wall turbulent motions
论文作者
论文摘要
通过改善Baars等人的预测性内在模型，将湍流通道流中的近壁湍流速度分解为$ y^+<100 $的小尺度和大型组件。 [物理。流体修订版1，054406（2016）]，其中$ y^+$是粘性标准化的壁正常高度。通过将对数层的中心降低到$ y^+= 100 $的外部参考高度（模型中的参数）来获得小尺度，这可以完全消除外部影响。另一方面，大规模代表了外部能量动作的近壁脚印。我们提供了很多证据，这些证据表明，小规模的动作是雷诺的，随着粘性缩放的速度，在摩擦雷诺数在1000到5200之间的数字。在180到600的较低的雷诺数下，小规模无法通过粘稠的单元和vort的结构来缩放。负责异常缩放行为。最后，发现外部大规模足迹的一个小规模可以通过粘性单元很好地缩放。
Near-wall turbulent velocities in turbulent channel flows are decomposed into small-scale and large-scale components at $y^+<100$ by improving the predictive inner-outer model of Baars et al. [Phys. Rev. Fluids 1, 054406 (2016)], where $y^+$ is the viscous-normalized wall-normal height. The small-scale one is obtained by reducing the outer reference height (a parameter in the model) from the center of the logarithmic layer to $y^+=100$, which can fully remove outer influences. On the other hand, the large-scale one represents the near-wall footprints of outer energy-containing motions. We present plenty of evidences that demonstrate that the small-scale motions are Reynolds-number invariant with the viscous scaling, at friction Reynolds numbers between 1000 and 5200. At lower Reynolds numbers from 180 to 600, the small scales can not be scaled by the viscous units, and the vortical structures are progressively strengthened as Reynolds number increases, which is proposed as a possible mechanism responsible for the anomalous scaling behavior. Finally, it is found that a small-scale part of the outer large-scale footprint can be well scaled by the viscous units.
